1. Field of the Invention
The invention concerns a topical skin preparation for the treatment of acne, seborrheic dermatitis and other skin diseases.
2. Description of Related Art
Acne is a well known and common skin disease. It has very different forms as well as grades of severity, from the so-called "pubertary pimples" i.e., a simple acne vulgaris, extending to the more dangerous forms such as acne conglobate, which can lead to severe disfigurements of the skin. It is estimated that about one quarter of all young people in the industrialized countries suffer from acne with a culmination age at 15-18 years. The disease acne seems to be generally on the increase. According to a Swiss study, the percentage of acne patients at the University Hospital of Basle increased by ten times from 1920 to 1980. While the maximum age formerly was 25 years, acne patients 50 years of age are as common today. Women of advanced age are clearly affected stronger than men. It can be assumed that the reason is the increasing stress of the skin by environmental influences and improper cosmetics.
Since acne generally is not life endangering and is regarded by some as a kind of pubertary consequence, only a small part of the people with acne have regular medical treatment. Yet a significant percentage of the population is plagued by this disease. Both disregarding it, as well as excessive and improper treatment, can lead to irreversible scars and changes of the skin, and consequent adverse effects to quality of life.
To a large extent, the aforementioned is also true for seborrheic dermatitis and other skin diseases in their different forms such as herpes, from simple irritations of the skin up to severe and irreversible changes of epidermis. For distinguishing of these diseases and in order to define their grade, dermatology uses defined terms which can be measured or counted to a high degree. Acne in its different forms such as acne aestivalis, fulminans, necroticans, cosmetica etc. is mostly defined by papules, pustules, blackheads and whiteheads, while seborrheic dermatitis and related skin diseases are generally characterized by itching, scales and erythema.
There are basically two possibilities for the therapy of acne, seborrheic dermatitis and other related skin diseases: Topical (exterior) treatment and oral treatment which is effective via the metabolism. The oral treatment is principally used only for very severe forms of acne, since retinoids and related active agents may have very strong side effects. In addition, women are endangered during their pregnancy. But even the topical remedies used up to now are not totally safe when applied at the concentration necessary for the desired therapeutic effect. Antibiotic preparations, mainly used for fighting secondary infections, are generally subject to prescription. In addition, benzoylperoxide, which is the topical remedy most used, is by no means as harmless as it would be desirable for at least the treatment of young people. In addition to its suspected carcinogenic effect established in tests with animals, it is very aggressive, and its main effect consists of the oxidation of the upper skin layers like a chemical scalpel, thereby chemically isolating these layers and causing irritation. The same applies for salicylic acid which is used to dissolve the skin by its keratolytic effect. Generally it can be stated that up to now no remedy is available with both good efficacy and skin tolerability.
It is known that salt solutions can have manifold, mainly positive effects on the skin. Well-known is the shrinking of the skin in ocean water when swimming for a long time, which is caused by osmotic effects. In some cases, upon frequent bathing in sea water, a slight reduction of acne and less itching with seborrheic dermatitis have been observed. This therapeutic effect, however, is negligibly weak and limited to isolated cases.
The effect of the Dead Sea waters on psoriasis has been therapeutically proven since ancient times. In connection with this treatment, spontaneous healings of acne have also been observed, but in a much too small number to justify such treatment.
In U.S. Pat. No. 4,943,432, a synthetic salt mixture for the treatment of psoriasis is described. This salt mixture has the following preferred ionic composition:
Magnesium 20-285 Chloride 20-750 Sodium 11-266 Bromide 0.2-29 Calcium 2-235 Sulfate 0.2-22 Potassium 2-95 Borate 0.05-14 Strontium 0.02-10.5 Silicate 0.02-14 Iron 0.02-8.5 Fluoride 0.001-11 Aluminum 0.001-6.0 Iodide 0.001-9.5 Zinc 0.001-2.5 Carbonate 0.0002-9.0 Lithium 0.001-2.0 Hydrogen- 0.0001-8.5 carbonate
Psoriasis is treated with extremely good results using this salt mixture, either as a bath solution or topically applied in the form of a gel. Yet, therapeutic practice has shown that, contrary to the good healing effect on psoriasis, other skin diseases such as acne and seborrheic dermatitis are not influenced as much as would be desired.
Testing has established that, contrary to psoriasis, the effect of the salt mixtures described in the above-mentioned patents was statistically ineffective for treatment of acne and seborrheic dermatitis with a bathing treatment. When such a salt mixture was used gelified with cellulose ether, it also proved to be statistically ineffective for treatment of these conditions.
Accordingly, an object of the invention is to provide a salt mixture composition for the treatment of acne, seborrheic dermatitis and other related skin diseases which, contrary to the treatments known so far, combines a high specific efficacy while avoiding overall adverse effect to the skin and physiology.